A plastic track for toy cars and a windshield wiper that sweeps intermittently seem pretty insignificant in the world of business. But both have created big legal headaches lately for some of the nation's largest corporations. Those products were the subject of patent infringement lawsuits, and all appear to be heading toward multimillion-dollar paydays for the people who contend that they first patented those ideas. Profit, it seems, is the father of invention.

Like miniature actors in a disjointed infomercial, students at Balboa Magnet School extolled the virtues of their inventions, appealing to their audience's most basic needs. "Are you tired of getting milk for your child?" one second-grader asked his audience. "Are you tired of cleaning up the mess your child makes when he's trying to get it himself?" Well, Timothy Shin's new no-muss, no-fuss contraption that pumps milk into a glass promises kids "independence in getting their own drink."

With her love of geography and inventing, Vicenta Ortiz, 9, thought it was only natural to build an electronic game that tests a person's knowledge of the world. Along with a couple of her friends from George Washington Carver Elementary School, Vicenta helped design a trivia game, which lights up a small bulb when a player answers a question correctly. "It's fun to do things with science. We can help people learn about geography," she said.

For 5-year-old Ashley Fuller, thinking of an invention for Rossmoor Elementary School's "Invent America" contest was easy. The blonde kindergartner just recalled the time her family was flying home when a sister's dinner tray fell into her lap. To avoid future mishaps, Ashley invented "Sticky Meals," a lap tray with Velcro on it to secure a drinking glass and dinner plate.

A youthful motorcyclist who developed a new, rough-terrain suspension system for his cycle won an award that could total $19 million from Suzuki Motor Co. Friday when a jury decided that the mammoth Japanese manufacturer had stolen his invention. A federal court jury in Los Angeles decided Don Richardson, a lifelong motorcycle enthusiast, should be entitled to worldwide royalties for the unique floating shock absorber that he designed at the age of 19.

Irvine Valley College's annual invention fair over the weekend drew more than 750 people, who examined the creations of local elementary and junior high school students. About 300 students from Irvine and Tustin schools on Saturday displayed their often unusual inventions, which ranged from a toothbrush for people with braces to a bike-riding visor.

Trouble waking up? Why not try an alarm clock that squirts water as it goes off? If this sounds like a refreshing concept, start saving now. One may be on the market before you know it. The aquatic alarm--along with several other inventions to overcome everyday roadblocks--was featured Friday at Balboa Magnet Elementary School as 60 parents crowded into a third-grade classroom to witness the school's fourth annual "Invention Convention."

Don't expect 80-year-old retiree Harry Hahn to sit back helplessly and accept new aches and inconveniences. No, this Huntington Beach man is determined to solve such problems. Calling on his years of experience as a model-maker at Mattel toys and lifelong habit of tinkering, he builds seemingly wacky inventions that make life--or at least his life--a little easier. When in-grown toenails bothered him, he created "Toe-Tab," a bandage-like device that forces the nail to grow away from the flesh.

On a list of inventions that we would be better off without, nuclear weapons would surely come first. Not that they don't have their champions. It is argued that nuclear weapons have been a boon to mankind by making war among the great powers too horrible to contemplate. At a subnuclear level, most readers who have written me on the subject think the most pernicious of inventions is television; the automobile comes in second. Helene Marshall of Camarillo says that we have been dehumanized by TV.